Nicholas Kyriakopoulos

A comparative analysis of network dependability, fault-tolerance, reliability, security, and survivability

A number of qualitative and quantitative terms are used to describe the performance of what has come to be known as information systems, networks or infrastructures. However, some of these terms either have overlapping meanings or contain ambiguities in their definitions presenting problems to those who attempt a rigorous evaluation of the performance of such systems. The phenomenon arises because the wide range of disciplines covered by the term information technology have developed their own distinct terminologies. This paper presents a systematic approach for determining common and complementary characteristics of five widely-used concepts, dependability, fault-tolerance, reliability, security, and survivability. The approach consists of comparing definitions, attributes, and evaluation measures for each of the five concepts and developing corresponding relations. Removing redundancies and clarifying ambiguities will help the mapping of broad user-specified requirements into objective performance parameters for analyzing and designing information infrastructures.

A new instrumented approach for translating American Sign Language into sound and text

This work discusses an approach for capturing and translating isolated gestures of American Sign Language into spoken and written words. The instrumented part of the system combines an AcceleGlove and a two-link arm skeleton. Gestures of the American Sign Language are broken down into unique sequences of phonemes called poses and movements, recognized by software modules trained and tested independently on volunteers with different hand sizes and signing ability. Recognition rates of independent modules reached up to 100% for 42 postures, orientations, 11 locations and 7 movements using linear classification. The overall sign recognizer was tested using a subset of the American Sign Language dictionary comprised by 30 one-handed signs, achieving 98% accuracy. The system proved to be scalable: when the lexicon was extended to 176 signs and tested without retraining, the accuracy was 95%. This represents an improvement over classification based on hidden Markov models (HMMs) and neural networks (NNs).

The AcceleGlove: a whole-hand input device for virtual reality

We present The AcceleGlove, a novel whole-hand input device to manipulate three different virtual objects: a virtual hand, icons on a virtual desktop and a virtual keyboard using the 26 postures of the American Sign Language (ASL) alphabet.

Environmental Sample Analysis

Environmental sample analysis is not a new verification method. It has been applied ever since the first nuclear weapons were produced and tested and related national technical means played a major role in verifying compliance with the Partial Test Bean Treaty of 1963. However, scientific progresses in measurement technologies and source location methods as well as major verification applications for nuclear arms control (UNSCOM/UNMOVIC since 1990 and CTBT since 1996) in recent years have brought significant progress. New opportunities are being explored with regard to wide-area environmental sampling according to the NPT Additional Protocol (model agreement of 1997). Further proposals include the to-be-negotiated Fissile Materials Cut-off Treaty (Shannon Mandate of 1995) as well as bilateral or regional agreements on cooperative environmental monitoring as confidence building measures.

Network Dependability, Fault-tolerance, Reliability, Security, Survivability: A Framework for Comparative Analysis

A number of qualitative and quantitative terms are used to describe the performance of what has come to be known as information systems, networks or infrastructures. However, some of these terms either have overlapping meanings or contain ambiguities in their definitions presenting problems to those who attempt a rigorous evaluation of the performance of such systems. The phenomenon arises because the wide range of disciplines covered by the term information technology have developed their own distinct terminologies. This paper presents a systematic approach for determining common and complementary characteristics of five widely-used concepts, dependability, fault-tolerance, reliability, security, and survivability. The approach consists of comparing definitions, attributes, and evaluation measures for each of the five concepts and developing corresponding relations. Removing redundancies and clarifying ambiguities will help the mapping of broad user-specified requirements into objective performance parameters for analyzing and designing information infrastructures

QoS Mapping: A Framework Model for Mapping Network Loss to Application Loss

Todays Internet provides only a single Class of Service (CoS) to all of its services (e.g., Multimedia, Data, Audio), namely the best-effort service. This service does not make any guarantees on the Quality of Service (QoS) an application receives. The continuous demands for QoS guarantees have led to the introduction of various network-layer mechanisms that provide some end-to-end QoS assurance including MPLS, Integrated Service Model (IntServ), and Differentiated Service Model (DiffServ). However, the QoS mapping between the network-layer and the application-layer is still a challenge and needs to be addressed. To guarantee and end-to-end QoS, it is essential to map QoS parameters between these layers. A framework for investigating the mapping of the packet loss rate as an important QoS parameter is presented here. The network QoS performance characteristic for the loss parameter is mapped from lower to upper layer in a quantifiable way.

Towards a Standardized Terminology for Network Performance

The integration of the products of diverse fields, including the human component, into complex systems has created major difficulties in the development of efficient mechanisms for analyzing system performance. One of the problems can be traced to the variety of terminologies used in describing performance across different fields. A designer or user is faced with vague terms that may be complementary, synonymous, or some combination thereof. There is a need to develop a common understanding of the meaning of widely used terms without reference to a specific discipline. The work described in this paper aims to develop a framework that helps identify a set of performance indicators for complex systems, such as information infrastructures. The objective is not to propose yet another concept, but rather to identify from the existing concepts the proper definitions, attributes, intersections, and evaluation measures. Dependability, fault-tolerance, reliability/availability, security, and survivability are used as representative examples for describing the proposed framework. This framework could eventually help furnish the basis towards adoption of standard terminology.

Phonocardiography nonlinear multiple measurements in discovering the abnormalities in the bioprosthetic heart valves

This paper describes the benefit for potentially rectifying the multiple nonlinear Phonocardiography measurements so that we can apply the linear independent component analysis (ICA) to separate blindly the sources of heart valve murmuring in order to find a noninvasive way to discover abnormalities in the Bioprosthetic heart valves. At the beginning the paper will discuss a new design of measurement of the PCG signal based on the (ICA). The second part of the paper will show a comparison between the classification using the classical Fourier transform as a source of features and using the ICA sources of the same features. The last part of this paper will discuss various ways to overcome the nonlinear square detect law, and the lack of multiple independent readings, which is essential in the implementation of the ICA algorithm.

The Information Infrastructure of a Treaty Monitoring System

The information infrastructures for arms control treaties are complex systems, because they are global and they generate outputs which may have major impact on the stability of the international security system. The information services they provide may make the difference between war and peace. Consequently, they need to be designed in such a manner that the quality of these services is commensurate with their importance. In this chapter we have identified the attributes of validity, sufficiency, integrity and timeliness to describe and measure the quality of the information services expected to be provided by a treaty information infrastructure. We have also presented the outline of a systematic approach for translating these service attributes into system design specifications. Essential to this approach is a properly designed infrastructure information management system. Without it one would never know whether or not the quality of services required by the treaty verification regime is, in effect, provided by the information infrastructure.

Modeling for Risk in the Absence of Sufficient Data: A Strategy for Treaty Verification

This paper presents a methodology for selecting facilities to be inspected combining game theory with qualitative measures of risk. The Chemical Weapons Convention is used as an illustrative example.